The United States has two P-8 Poseidon aircraft searching in the Indian Ocean, Army Col. Steve Warren said.

Navy aircraft supporting the search have flown 24 missions, with 220 hours of flight time covering 336,000 square nautical miles, according to a U.S. 7th Fleet news release.

“Additionally, we have two pieces of highly sophisticated underwater detection equipment [engaged in the search] -- the towed pinger locator and the Bluefin-21 [sidescan sonar],” Warren said.

Both underwater devices are operating from the Australian defense vessel Ocean Shield, the news release said.

The team operating the towed pinger locator detected signals yesterday that are consistent with sounds that would come from a black box, the release said. The signals were detected on at least three separate occasions for extended periods of time and at several different depths. The locator also detected two signals at the same frequency, but in different locations, which would be consistent with signals transmitted by both a flight data recorder and cockpit voice recorder, the release noted.

The team is working to reacquire the signal and plans to use the Bluefin-21 to create a picture of any potential wreckage.

The search is a round-the-clock operation, and is currently focused on an area about 950 nautical miles northwest of Perth, Australia.

Determining the location and position of search assets is “a very collaborative effort between Americans, the Australians, the Malaysians and others,” Warren said. But, he added, “the Australians right now do have the lead.”